BARCELONA, Nov 15 (Reuters) - A series of cabinet resignations in Britain over a draft divorce deal with the European Union reinforces uncertainties over the future of the country's ad market, the co-chief executive of outdoor advertising company JCDecaux said on Thursday. Just over 12 hours after British Prime Minister Theresa May announced that her team of top ministers had agreed to the terms of the draft agreement, Brexit minister Dominic Raab and work and pensions minister Esther McVey quit, saying they could not support it.

"The situation is obviously very serious," Jean-Charles Decaux told Reuters in an interview on the sidelines of the Morgan Stanley TMT conference in Barcelona.

"Today's events reinforce the uncertainties in this market," the French company's executive added.

JCDecaux, the world's leading outdoor advertising company, manages the bus shelter advertising concession by Transport for London (TfL). Britain is its third biggest market and represents 10 percent of its total revenues. (Reporting by Mathieu Rosemain; editing by Michel Rose)